Synthetic doors have become a common place as a replacement for the traditional wooden doors in residences and other building applications. Often such synthetic doors are formed of fiber glass sheets (skins) attached to opposite sides of a rectangular frame forming the stiles and rails of the door with resulting cavity between the sheets filled with a foam. Doors so constructed do not warp, are not subject to insect infestation and are resistant to the elements. Moreover such doors can include graining on the outer surfaces of the skins which gives them the appearance of a natural wood fabricated product.
Traditionally the molded skins for making doors of the type disclosed in U.S. Pat. No. 3,950,894 issued to DiMaio and in U.S. Pat. No. 4,550,540 issued to Thorn are constructed using mixtures having by weight 12% to 15% polyester resin, 5% to 15% polystyrene, 40% to 50% calcium carbonate and 15% to 25% chopped fiberglass. Such mixtures are placed in a layer in a compression molding machine and subjected to pressures from 600 to 1,500 psi for a cure cycle from 60 to 200 seconds. Such mixtures are usually referred to ‘sheet molding compounds’ [SMCs] and are normally constructed of thermoset materials such as phenolics, urea, melamines and polyesters. A general description of the sheet molding process is found in an article entitled, “Compression Molding” by N. D. Simons in Modern Plastics Encyclopedia, Vol. 54 No. 10A (1977–78).
Skins formed from such processes for doors have a thicknesses of from about 0.05 inches to about 0.20 inches, depending on the door application in which they are used.
Other door constructions employ metal skins mounted on a rectangular frame in place of the sheet molded skins described above. Such structures also have a core which is filled with a plastic foam but a different method is often employed to attach the metal skins to the rectangular frame which is typically constructed of wooden stiles and rails, but also may be constructed of plastic materials.
As previously noted such skins are affixed to opposite sides of a rectangular frame and core enclosed by the frame and skins are filled with a foam to complete the door such as illustrated in FIGS. 1 and 2 accompanying this application. The core is typically composed of a rigid urethane foam having a density of 0.8 pounds per cubic foot to 3.5 pounds per cubic foot. The cross section of such prior art doors is illustrated in FIG. 2 where it can be seen that the central portion of such doors contain little structure for attaching window lights and the like, such as are shown installed on the door in FIG. 3. Moreover once the cut outs are made for the window lights in such a door, care must be exercised not to collapse the rigid urethane foam since the foam is not resilient whether the skins are of metal or sheet molded compositions.
In the past frames have been used which employ screws to attached frame members on opposite sides of a door. Since the frames are typically made of plastics, this requires that plugs be inserted in the recessed screw holes. Such plugs often distract from the appearance of the exposed surfaces of the frame because the plugs are made in a different injection molding machine being slightly off color and disfiguration from gluing them in the holes.
It is an object of this invention to provide a frame system which will ensure that a window light held by the frame system will be properly installed in an opening formed in the door in a tight, weather resistant unit without numerous fasteners defacing the outer surfaces of the frame system which is a problem with prior art frame systems.
It is also an object of the current invention to provide a frame system that functions as a shipping container for its associated window light by including dowels and guide pins on the several frame members which allow the frame system to be assembled in a non-locking relationship during shipping and converted to a locking engagement relationship when installed.
Another object of the invention is to provide a frame system which can be field installed which enables contractors to select different window lights for synthetic doors available in the market place.
It is also an object to provide an efficient and quick process for installing window lights in doors in the field which requires minimum effort.
Other objects will be apparent when viewing the descriptions of the invention which follows.